Open system (systems theory)

An open system is a system which continuously interacts with its environment. The interaction can take the form of information, energy, or material transfers into or out of the system boundary, depending on the discipline which defines the concept (see below). An open system should be contrasted with the concept of an isolated system which exchanges neither energy, matter, or information with its environment.

The concept of an "open system" was formalized within a framework that enabled one to interrelate the theory of the organism, thermodynamics, and evolutionary theory.^[1] This concept was expanded upon with the advent of information theory and subsequently systems theory. Today the concept has its applications in the natural and social sciences.

Contents 1 In the natural sciences 2 In the social sciences 3 See also 4 References 5 Further reading 6 External links

[edit] In the natural sciences

Thermodynamics

Branches Classical · Statistical · Chemical Equilibrium / Non-equilibrium Thermofluids Laws Zeroth · First · Second · Third Systems State: Equation of state · Ideal gas · Real gas Phase of matter · Equilibrium Instruments (heat bath, reservoir) Processes: Isobaric · Isochoric · Isothermal Adiabatic · Isentropic · Isenthalpic Quasistatic · Polytropic Reversibility · Endoreversibility · Irreversibility Cycles: Heat engines · Heat pumps Thermal efficiency System properties Property diagrams Intensive and extensive properties State functions: Temperature / Entropy (intro.) † Pressure / Volume (specific) † Chemical potential / Particle number † († Conjugate variables) Reduced properties Process functions: Work · Heat Material properties Specific heat capacity  c = T N Compressibility  β = − 1 V Thermal expansion  α = 1 V Property database Equations Carnot's theorem Clausius theorem Fundamental relation Ideal gas law Maxwell relations Table of thermodynamic equations Potentials Free energy · Free entropy Internal energy U(S,V) Enthalpy H(S,p) = U + pV Helmholtz free energy A(T,V) = U − TS Gibbs free energy G(T,p) = H − TS History and Culture Philosophy: Entropy and time · Entropy and life Brownian ratchet · Maxwell's demon Heat death paradox · Loschmidt's paradox Synergetics History: General · Heat · Entropy · Gas laws Perpetual motion Theories: Caloric theory · Vis viva · Theory of heat Mechanical equivalent of heat · Motive power Publications: "An Experimental Enquiry Concerning ... Heat" "On the Equilibrium of Heterogeneous Substances" "Reflections on the Motive Power of Fire" Timelines of: Thermodynamics · Heat engines Art: Maxwell's thermodynamic surface Scientists Daniel Bernoulli Sadi Carnot Benoît Paul Émile Clapeyron Rudolf Clausius Hermann von Helmholtz Julius Robert von Mayer William Rankine John Smeaton Georg Ernst Stahl Benjamin Thompson William Thomson John James Waterston

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In the natural sciences an open system is one whose border is permeable to both energy and mass.^[2] In physics a closed system, by contrast, is permeable to energy but not to matter.

Open systems have a number of consequences. A closed system contains limited energies. The definition of an open system assumes that there are supplies of energy that cannot be depleted; in practice, this energy is supplied from some source in the surrounding environment, which can be treated as infinite for the purposes of study. One type of open system is the so-called radiant energy system, which receives its energy from solar radiation – an energy source that can be regarded as inexhaustible for all practical purposes.

They are also known as OSM.

[edit] In the social sciences

In the social sciences an open system is a process that exchanges material, energy, people, capital and information with its environment.

[edit] See also

• Business process
• Complex system
• Dynamical system
• Glossary of systems theory
• Isolated system
• Maximum power principle
• Non-equilibrium thermodynamics
• Open system (computing)
• Open System Environment Reference Model
• Openness
• Open and Closed Systems in Social Science
• Phantom loop
• System theory
• Thermodynamic system

[edit] References

1. ^ Luhmann, Niklas. Social Systems. Stanford: Stanford University Press, 1995; pp. 6-7
2. ^ Glossary Maxwell Demon, 1998.

[edit] Further reading

• Khalil, E.L. (1995). Nonlinear thermodynamics and social science modeling: fad cycles, cultural development and identificational slips. The American Journal of Economics and Sociology, Vol. 54, Issue 4, pp. 423–438.
• Weber, B.H. (1989). Ethical Implications Of The Interface Of Natural And Artificial Systems. Delicate Balance: Technics, Culture and Consequences: Conference Proceedings for the Institute of Electrical and Electronic Engineers.

[edit] External links

• OPEN SYSTEM, Pricipea Cybernetica Web, 2007.

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